Khan said the rally was being held by the Awami National Party, whose members have been repeatedly targeted by fighters.

A provincial cabinet minister from the party, Bashir Balour, was killed in the attack, which was claimed by the Pakistani Taliban. Balour often spoke out against the group.

"The bombing occurred in a congested part of Peshawar city at the residence of one of the party workers," Al Jazeera's Kamal Hyder said, reporting from Lahore.

"As the meeting came to end, Balour was coming out with his security personnel," our correspondent said. "The suicide bomber got close to him, and he was wounded in the chest and stomach then rushed to a nearby hospital."

"The doctors tried to save Balour. However, he succumbed to his wounds and died at the hospital."

Balour was the brother of the Pakistani railways minister who put a bounty on the California film-maker who produced the anti-Islam video which caused mass protests in September.